55 research outputs found

    Incorporating social opinion in the evolution of an epidemic spread

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    The evolution of the COVID19 pandemic worldwide has shown that the most common and effective strategy to control it used worldwide involve imposing mobility constrains to the population. A determinant factor in the success of such policies is the cooperation of the population involved but this is something, at least, difficult to measure. In this manuscript, we propose a method to incorporate in epidemic models empirical data accounting for the society predisposition to cooperate with the mobility restriction policiesThis research is supported by the Spanish Ministerio de EconomĂ­a y Competitividad and European Regional Development Fund, research grant No. COV20/00617 and RTI2018-097063-B-I00 AEI/FEDER, UE; by Xunta de Galicia, Research Grant No. 2018-PG082, and the CRETUS Strategic Partnership, AGRUP2015/02, supported by Xunta de Galicia. All these programs are co-funded by FEDER (UE). We also acknowledge support from the Portuguese Foundation for Science and Technology (FCT) within the Project n. 147S

    Assessing the risk of pandemic outbreaks across municipalities with mathematical descriptors based on age and mobility restrictions

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    By March 14th 2022, Spain is suffering the sixth wave of the COVID-19 pandemic. All the previous waves have been intimately related to the degree of imposed mobility restrictions and its consequent release. Certain factors explain the incidence of the virus across regions revealing the weak locations that probably require some medical reinforcements. The most relevant ones relate with mobility restrictions by age and administrative competence, i.e., spatial constrains. In this work, we aim to find a mathematical descriptor that could identify the critical communities that are more likely to suffer pandemic outbreaks and, at the same time, to estimate the impact of different mobility restrictions. We analyze the incidence of the virus in combination with mobility flows during the so-called second wave (roughly from August 1st to November 30th, 2020) using a SEIR compartmental model. After that, we derive a mathematical descriptor based on linear stability theory that quantifies the potential impact of becoming a hotspot. Once the model is validated, we consider different confinement scenarios and containment protocols aimed to control the virus spreading. The main findings from our simulations suggest that the confinement of the economically non-active individuals may result in a significant reduction of risk, whose effects are equivalent to the confinement of the total population. This study is conducted across the totality of municipalities in SpainS

    Effects of different arachidonic acid supplementation on psychomotor development in very preterm infants; A randomized controlled trial

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    Background & aims: Nutritional supplementation with polyunsaturated fatty acids is important in preterm infants neurodevelopment, but it is not known if the omega-6/omega-3 ratio affects this process. This study was designed to determine the effects of a balanced contribution of arachidonic acid in very preterm newborns fed with formula milk. Methods: This was a randomized trial, in which newborns <1500 g and/or <32 weeks gestational age were assigned to one of two groups, based on the milk formula they would receive during the first year of life. Initially, 60 newborns entered the study, but ultimately, group A was composed of 24 newborns, who were given formula milk with an ω-6/ ω-3 ratio of 2/1, and Group B was composed of 21 newborns, given formula milk with an ω-6/ω-3 ratio of 1/1. The infants were followed up for two years: growth, visual-evoked potentials, brainstem auditory-evoked potentials, and plasma fatty acids were periodically measured, and psychomotor development was assessed using the Brunet LĂ©zine scale at 24 months corrected age. A control group, for comparison of Brunet LĂ©zine score, was made up of 25 newborns from the SEN1500 project, who were fed exclusively with breast milk. Results: At 12 months, arachidonic acid values were significantly higher in group A than in group B (6.95 ± 1.55 % vs. 4.55 ± 0.78 %), as were polyunsaturated fatty acids (41.02 ± 2.09 % vs. 38.08 ± 2.32 %) achieved a higher average. Group A achieved a higher average Brunet LĂ©zine score at 24 months than group B (99.9 ± 9 vs. 90.8 ± 11, p =0.028). The Brunet LĂ©zine results from group A were compared with the control group results, with very similar scores registered between the two groups (99.9 ± 9 vs. 100.5 ± 7). There were no significant differences in growth or evoked potentials between the two formula groups. Conclusions: Very preterm infants who received formula with an ω-6/ω-3 ratio of 2/1 had higher blood levels of essential fatty acids during the first year of life, and better psychomotor development, compared with very preterm newborns who consumed formula with an ω-6/ω-3 of 1/1. Therefore, formula milk with an arachidonic acid quantity double that of docosahexaenoic acid should be considered for feeding very preterm infants

    Intermittency regimes of poorly-mixed chemical oscillators

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    Perfect mixing or interaction between oscillators is almost never achieved under experimental conditions and, nevertheless, it might be crucial in understanding the observed phenomena. We propose a mathematical model that directly introduces the degree of mixing and analyze the consequences on the synchronization patterns observed. For that we considered catalyst-loaded chemical oscillators as they represent a paradigm for synchronization phenomena from the experimental and numerical point of view. In this study we explore a modified 3-variable Oregonator model where the active surrounding solution is discretized as oscillators themselves and a discrete radius of chemical exchange is introduced to account for spatial distribution and movement dynamics. We found that for low-to none levels of mixing in the system, a series of irregular states appear on the edge of phase transitions among dynamical regimes, and that several novel non-fully synchronized behaviors appear for a small window in the parameter spaceS
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